Propolis is a resinous substance produced by
honeybees that possesses many biological activities, such as antitumor, antioxidant, antimicrobial, anti-inflammatory,
and immunomodulatory, among others. The purpose of
the present study was to investigate the biochemical profile of propolis-treated rats to observe
whether propolis might lead to side effects after
administration. Three different treatments were analyzed: (1) rats were treated
with different concentrations of propolis (1, 3 and
6mg/kg/day) during 30 days; (2) rats were treated with 1mg/kg/day of ethanolic or water extracts of propolis
(EEP, WEP) during 30 days; (3) rats were treated with 1mg/kg/day of ethanolic extract of propolis
during 90 and 150 days. Our results demonstrated no alterations in the seric levels of cholesterol, HDL-cholesterol, total lipids,
triglycerides and in the specific activity of aminotransferases
(AST) and lactic dehydrogenase (LDH) of propolis-treated groups when compared to controls. On the
basis of our findings, since propolis does not induce
any significant change in seric parameters, it is
claimed that long-term administration of propolis
might not have any cardiac injury.

The present study examines the effects of a hypercaloric
diet on hepatic glucose metabolism of young rats, with and without monosodium
glutamate (MSG) administration, and the association of these treatments with
evaluating markers of oxidative stress. Male weaned Wistar
rats (21 days old) from mothers fed with a hypercaloric
diet or a normal diet, were divided into four groups (n=6): control (C) fed
with control diet; (MSG) treated with MSG (4 mg/g) and control diet; (HD) fed
with hypercaloric diet and (MSG-HD) treated with MSG
and HD. Rats were sacrificed after the oral glucose tolerance test (OGTT), at
45 days of treatments. Serum was used for insulin determination. Glycogen, hexokinase(HK),
glucose-6-phosphatase(G6PH), lipid hydroperoxide, superoxidedismutase(SOD) and
glutathione peroxidase(GSH-Px)
were determined in liver. HD rats showed hypoglycemia,
hyperinsulinemia, and high hepatic glycogen, HK and
decreased G6PH. MSG and MSG-HD had hyperinsulinemia, hyperglycemia, decreased HK and increased G6PH in hepatic
tissue. These animals had impaired OGTT. HD, MSG and MSG-HD groups had
increased lipid hydroperoxide and decreased SOD in
hepatic tissue. Hypercaloric diet and monosodium
glutamate administration induced alterations in metabolic rate of glucose
utilization and decreased antioxidant defenses. Therefore,
the hepatic glucose metabolic shifting induced by HD intake and MSG
administration were associated with oxidative stress in hepatic tissue.

Myosin-V,
an unconventional myosin, has two notable structural features: (i) a regulatory neck domain having six IQ motifs that bind calmodulin and light chains, and (ii) a structurally
distinct tail domain likely responsible for its specific intracellular
interactions. Myosin-V copurifies with synaptic
vesicles via its tail domain, which also is a substrate for calmodulin-dependent
protein kinase II. We demonstrate here that myosin-V coimmunoprecipitates with CaM-kinase
II from a Triton X-100-solubilized fraction of isolated nerve terminals. The purified proteins also coimmunoprecipitate
from dilute solutions and bind in overlay experiments on Western blots. The
binding region on myosin-V was mapped to its proximal and medial tail domains. AutophosphorylatedCaM-kinase II
binds to the tail domain of myosin-V with an apparent Kd of 7.7 nM. Surprisingly,
myosin-V activates CaM-kinase II activity in a
Ca2+-dependent manner, without the need for additional CaM. The apparent activation constants for the
autophosphorylation of CaM-kinase
II were 10 and 26 nM, respectively, for myosin-V
versus CaM. The
maximum incorporation of 32P into CaM-kinase II
activated by myosin-V was twice that for CaM, suggesting that myosin-V binding to CaM-kinase II entails alterations in kinetic and/or phosphorylation site parameters. These data suggest that
myosin-V, a calmodulin-carrying myosin, binds to and
delivers CaM to CaM-kinase
II, a calmodulin-dependent enzyme.

The subcellular localization in brain of an unconventional, calmodulin-binding myosin (myosin-V) found in neurons, astrocytes and other secretory
cells of vertebrates has been investigated by probing Western blots of synaptic
fractions from rat cerebral cortex with affinity-purified polyclonal antibodies
against myosin-V. Myosin-V was detected in intact synaptosomes
and in lysedsynaptosomes
associated with a particulate fraction. Our data suggest a role for brain
myosin-V in membrane-cytoskeleton function in the synaptic region.